Ahmadiahangar, R., Rosin, A., Palu, I., Azizi, A. On the concept of flexibility in electrical power systems : signs of inflexibility // Demand-side flexibility in smart grid. Singapore : Springer, 2020. p. 17-26. (Springer briefs in applied sciences and technology). https://doi.org/10.1007/978-981-15-4627-3_2